The present invention generally relates to a semiconductor device. More particularly, the present invention relates to a semiconductor comprising a fin-transistor and a method for fabricating the same.
In a fin-channel-array-transistor (“FCAT”), a channel width of fin channel transistors is determined by a short width of an active region mask. That is, since a width of a gate is equal to the short width of the active region mask in a semiconductor device [e.g., Dynamic Random Access Memory (“DRAM”)], the fin channel transistor should not be smaller than a length between source/drains adjacent to a channel width. The fin channel transistor can reduce the short channel effects (“SCE”) as the channel width becomes smaller, by increasing the effective channel width. However, there is a limit to how much the channel width of the fin channel transistor can be reduced because it is necessary to secure an area for the source/drain contact regions.
Since a recess gate mask for forming a fin channel transistor has a line/space type pattern, a gate electrode formed over a device isolation structure is separated from a storage node junction region by a gate insulating film, thereby increasing a parasitic capacitance of the gate electrode. The parasitic capacitance of the gate electrode degrades the operation speed of the cell transistor. Also, leakage current is increased in the storage node junction region due to a gate induced drain leakage (“GIDL”) effect, thereby degrading refresh characteristics of the DRAM.